A camshaft as used in automotive engines has typically been machined, shaped for its periphery (becoming a cam surface), using a dedicated machine tool tailored to achieve this end, known as a camshaft shaping or milling machine, or a camshaft shaper or miller.
A conventional camshaft shaping machine, as shown in FIGS. 1 and 2, includes a bed a on which a pair of work heads b are mounted as movable towards and away from each other. The work heads b have their faces opposing to each other to which chucks c are attached, respectively, with which a workpiece d introduced between them can be rotatably clamped as held at its opposed ends.
The bed a has also a cutter head e mounted thereon movably in a first direction longitudinally of the workpiece d as well as in a second, back and forth direction that is orthogonal to the first direction. With a disk shaped cutter or cutting tool g attached thereto as rotatable by a cutter drive motor f, the cutter head e is designed to be moved back and forth under commands of an NC (numerical control) unit to mill or shape with the rotating cutter g and thereby machine the workpiece d so as to develop a cam (profiled) surface therein.
Development in the recent years of a sophisticated, high performance engine has now brought about the need to provide a camshaft machined in a conical shape with its cam surface inclined with respect to the cam axis, thus the requirement for a dedicated machine tool with the ability to provide conical cams, which any conventional cam shaping machine entirely fails to possess.